Needle filter apparatus

Abstract

Disclosed is a disposable needle filter apparatus with a universal truncated syringe-receiving neck to enable the filtration of fluids/solutions aspirated into a needle-bearing syringe. The apparatus includes a needle seal stopper and needle stop to create a substantially airtight chamber to facilitate fluid aspiration through an enclosed filter and into the syringe. In an alternative embodiment, the filter apparatus includes an extended syringe-receiving neck configured to receive a specifically sized syringe/needle combination. In a further embodiment, the receiving neck is constructed as a modular unit to allow for interchangeable necks to accommodate different needle and syringe sizes with different cross-sectional diameters. In a yet further embodiment, the neck is constructed with stepped tapered segments of serially larger cross-sectional diameters to accommodate differently sized syringes. In a still further embodiment, the apparatus includes an accessory needle secured to the apparatus inlet.

What we claim as new and desire to secure by United States Letters Patent is: 
     
       1. A needle filter apparatus comprising:
 a filter housing having a first, upstream end with an inner upstream surface and a second, downstream end with an inner downstream surface, wherein the filter housing has portions defining a filter chamber; 
 a filter media secured in the filter chamber, wherein the filter media divides the filter chamber into an upstream side and a downstream side, wherein the upstream surface in combination with the filter media forms an upstream side gap, and wherein the downstream surface in combination with the filter media forms a downstream side gap; 
 a syringe-receiving neck extending from the second, downstream end of the filter housing, wherein the neck has portions defining a neck chamber in fluid communication with the filter chamber, and wherein the intersection of the syringe-receiving neck and the filter housing forms a neck/housing junction, wherein the cross-sectional diameter of the neck chamber is different than the cross-sectional diameter of the filter chamber; 
 a needle stop secured to, or formed in the syringe-receiving neck, wherein the needle stop is entirely within the neck chamber spaced from, or within, a plane occupied by the neck/housing junction; and, 
 a needle-sealing stopper secured in the receiving neck. 
 
     
     
       2. The filter apparatus of  claim 1  further comprising an inlet port extending from the first end of the filter housing wherein the inlet port has portions defining a channel in fluid communication with the filter chamber. 
     
     
       3. The filter apparatus of  claim 1  further comprising a stopper retention ring secured in the syringe-receiving neck, wherein the ring registers against the stopper and prevents stopper migration or removal from the neck. 
     
     
       4. The filter apparatus of  claim 3  wherein the ring further comprises an inner wall having a frustoconical shape in cross-section. 
     
     
       5. The filter apparatus of  claim 1  wherein the neck has an inner wall that defines the neck chamber and wherein the needle stop extends radially inwardly from the neck inner wall so as to intersect a centerline of the neck chamber. 
     
     
       6. A needle filter apparatus comprising:
 a filter housing having a first end and a second end and having portions defining a filter chamber; 
 a filter media secured in the filter chamber; 
 a syringe-receiving neck extending from the second end of the filter housing, wherein the neck has an inner wall that defines a neck chamber in fluid communication with the filter chamber; 
 a needle stop secured to, or formed in the neck chamber, wherein the needle stop extends radially inwardly from the neck inner wall so as to intersect a centerline of the neck chamber; and, 
 a needle-sealing stopper secured in the receiving neck, wherein the needle stop has a first end that extends downwardly toward, and in proximity to, the filter housing so as to create a gap between the needle stop and the filter housing, and a second end that extends upwardly along the neck inner wall to form a registration surface for the stopper. 
 
     
     
       7. The filter apparatus of  claim 6  wherein the needle stop extends within the neck chamber sufficient to prevent a needle from passing beyond the needle stop regardless of the angle or orientation of needle insertion into the apparatus. 
     
     
       8. The filter apparatus of  claim 1  wherein the needle stop comprises a needle strike plate suspended substantially centrally within the neck chamber between a plurality of spacer columns, wherein the spacer columns are secured to the neck inner wall, and wherein the substantially central location of the strike plate prevents a needle from passing beyond the needle stop regardless of the angle or orientation needle insertion into the apparatus. 
     
     
       9. The filter apparatus of  claim 8  wherein each of the plurality of space columns comprise a bottom and extending downwardly from the strike plate that collectively form a registration surface for registration against portions of the filter housing, and a top end extending upwardly from the strike plate that collectively form a registration surface for the stopper, wherein the bottom ends collectively create a cap between the filter and housing and a bottom of the strike plate, and wherein the top ends collectively create a gap between the stopper and a top surface of the strike plate. 
     
     
       10. The filter apparatus of  claim 9  wherein the strike plate comprises a plurality of inwardly scalloped perimeter regions formed between adjacent spacer columns of the plurality of spacer columns. 
     
     
       11. The filter apparatus of  claim 1  further comprising a pre-filter secured in the inlet upstream of the filter. 
     
     
       12. The filter apparatus of  claim 11  wherein the pre-filter has a plurality of pores ranging in size from about 10 μm to about 200 μm. 
     
     
       13. The filter apparatus of  claim 12  wherein the pre-filter is a single layer having at least one hydrophilic section and at least one hydrophobic section, wherein each section extends from an upstream surface to a downstream surface of the pre-filter. 
     
     
       14. The filter apparatus of  claim 11  wherein the pre-filter is selected from the group consisting of coarse sponges, screens, membranes having one or more layers, flat membranes, tubular or hollow fiber membranes and mixtures thereof. 
     
     
       15. The filter apparatus of  claim 11  wherein the pre-filter comprises a plurality of membrane layers, wherein the layers are all hydrophilic, hydrophobic or mixtures of hydrophilic and hydrophobic. 
     
     
       16. The filter apparatus of  claim 15  wherein at least one layer is either hydrophilic or hydrophobic and wherein the at least one layer has at least one section modified to have the opposite characteristic. 
     
     
       17. The filter apparatus of  claim 11  wherein the pre-filter is constructed from fibrous material including microfiber and nano-fiber material selected form the group consisting of polyethylene, polypropylene, nylon, polyester, carbon, fiberglass, polypropylene sulfide (PPS), Polytetrafluoro-ethylene (Teflon® PTFE), polyvinylidene fluoride (PVDF), polyacrylonitrile (PAN), Ethylene chlorotrifluoroethylene (ECTFE), polyethylene/ultra-high molecular weight polyethylene (PE/UPE), cellulose/diatomaceous earth or silica blends, cellulose/carbon particles or fibers, cellulose/ion exchange resins, cellulose acetate, nitrocellulose, polyethersulfone, polysulfone, cellulose acetate, polyvinylidene fluoride (PVDF), and other fluoropolymers such as perfluoroalkoxy (PFA) and its derivatives, MFA (co-polymer of tetrafluoroethylene and perfluoromethyl vinyl ether), fluorinated ethylene propylene polymer (FEP) and combinations thereof. 
     
     
       18. The filter apparatus of  claim 11  further comprising a second pre-filter. 
     
     
       19. The filter apparatus of  claim 18  wherein the second pre-filter has a plurality of pores ranging in size from about 0.2 micron to about 5 microns. 
     
     
       20. The filter apparatus of  claim 19  wherein the second pre-filter is a single layer having at least one hydrophilic section and at least one hydrophobic section, wherein each section extends from an upstream surface to a downstream surface of the second pre-filter. 
     
     
       21. The filter apparatus of  claim 18  wherein the second pre-filter is selected from the group consisting of coarse sponges, screens, membranes having one or more layers, flat membranes, tubular or hollow fiber membranes and mixtures thereof. 
     
     
       22. The filter apparatus of  claim 18  wherein the second pre-filter comprises a plurality of membrane layers, wherein the layers are all hydrophilic, hydrophobic or mixtures of hydrophilic and hydrophobic. 
     
     
       23. The filter apparatus of  claim 22  wherein at least one layer is either hydrophilic or hydrophobic and wherein the at last one layer has at least one section modified to have the opposite characteristics. 
     
     
       24. The filter apparatus of  claim 18  wherein the second pre-filter is constructed from fibrous material including microfiber and nano-fiber material and/or porous membrane selected from the group consisting of polyethylene, polypropylene, nylon, polyester, carbon, fiberglass, polypropylene sulfide (PPS), Polytetrafluoro-ethylene (Teflon® PTFE), polyvinylidene fluoride (PVDF), polyacrylonitrile (PAN), Ethylene chlorotrifluoroethylene (ECTFE), polyethylene/ultra-high molecular weight polyethylene (PE/UPE), cellulose/diatomaceous earth or silica blends, cellulose/carbon particles or fibers, cellulose/ion exchange resins, cellulose acetate, nitrocellulose, polyethersulfone, polysulfone, cellulose acetate, polyvinylidene fluoride (PVDF), and other fluoropolymers such as perfluoroalkoxy (PFA) and its derivatives, MFA (co-polymer of tetrafluoroethylene and perfluoromethyl vinyl ether), fluorinated ethylene propylene polymer (FEP) and combinations thereof. 
     
     
       25. The filter apparatus of  claim 1  wherein the filter has a plurality of pores ranging in size from about 0.01 μm to about 5 μm. 
     
     
       26. A needle filter apparatus comprising:
 a filter housing having a first end and a second end and having portions defining a filter chamber; 
 a filter media secured in the filter chamber, wherein the filter has a plurality of pores ranging in size from about 0.01 μm to about 5 μm, and wherein the filter is a single layer having at least one hydrophilic section and at least one hydrophobic section, wherein each section extends from an upstream surface to a downstream surface of the filter; 
 a syringe-receiving neck extending from the second end of the filter housing, wherein the neck has portions defining a neck chamber in fluid communication with the filter chamber; 
 a needle stop shoulder secured to, or formed in the neck chamber; and, 
 a needle-sealing stopper secured in the receiving neck. 
 
     
     
       27. The filter apparatus of  claim 1  wherein the filter is selected from the group consisting of membranes having one or more layers, flat membranes, tubular or hollow fiber membranes and mixtures thereof. 
     
     
       28. The filter apparatus of  claim 1  wherein the filter comprises a plurality of membrane layers, wherein the layers are all hydrophilic, hydrophobic or mixtures of hydrophilic and hydrophobic. 
     
     
       29. The filter apparatus of  claim 28  wherein at least one layer of the plurality of membrane layers is either hydrophilic or hydrophobic and wherein the at least one layer has at least one section modified to have the opposite characteristic. 
     
     
       30. The filter apparatus of  claim 1  wherein the filter is constructed from porous material selected from the group consisting of polyethylene, polypropylene, nylon, polyester, carbon, fiberglass, polypropylene sulfide (PPS), Polytetrafluoro-ethylene (Teflon® PTFE), polyvinylidene fluoride (PVDF), polyacrylonitrile (PAN), Ethylene chlorotrifluoroethylene (ECTFE), polyethylene/ultra-high molecular weight polyethylene (PE/UPE), cellulose/diatomaceous earth or silica blends, cellulose/carbon particles or fibers, cellulose/ion exchange resins, cellulose acetate, nitrocellulose, polyethersulfone, polysulfone, cellulose acetate, and other fluoropolymers such as perfluoroalkoxy (PFA) and its derivatives, MFA (co-polymer of tetrafluoroethylene and perfluoromethyl vinyl ether), fluorinated ethylene propylene polymer (FEP) and combinations thereof. 
     
     
       31. The filter apparatus of  claim 2  further comprising a needle secured to the inlet port. 
     
     
       32. The filter apparatus of  claim 1  further comprising an extension neck superposed about the syringe-receiving neck, wherein the extension neck is substantially hollow with stepped tapered segments of serially larger cross-sectional diameters. 
     
     
       33. The filter apparatus of  claim 1  further comprising a needle secured in the apparatus. 
     
     
       34. The filter apparatus of  claim 33  further comprising a needle-hub cap secured to a hub end of the needle. 
     
     
       35. The filter apparatus of  claim 1  further comprising a syringe needle secured in the syringe-receiving neck.